Quantitative salinity reconstructions of the Baltic Sea during the mid-Holocene
Ning, Wenxin LU ; Andersson, Per S. ; Ghosh, Anupam LU ; Khan, Mansoor and Filipsson, Helena L. LU
(2017)
In Boreas
46(1).
p.100-110
- Abstract
We reconstructed the past coastal environment of the Baltic Sea from c. 7300 to 3500 cal. a BP, with a focus on sea surface salinity (SSS). To quantitatively determine the SSS, two methods were employed: measurements of 87Sr/86Sr ratios in mollusc shells (SSSS r) and process length variations of dinoflagellate cysts Operculodinium centrocarpum (SSSpl). The SSSS r was ~6–7 between 6800 and 6400 cal. a BP, similar to modern conditions. Between 6000 and 3900 cal. a BP, SSSS r was consistently higher, ranging between ~9 and 13. Microfossils sensitive to salinity variations, such as Radiosperma corbiforum and... (More)
We reconstructed the past coastal environment of the Baltic Sea from c. 7300 to 3500 cal. a BP, with a focus on sea surface salinity (SSS). To quantitatively determine the SSS, two methods were employed: measurements of 87Sr/86Sr ratios in mollusc shells (SSSS r) and process length variations of dinoflagellate cysts Operculodinium centrocarpum (SSSpl). The SSSS r was ~6–7 between 6800 and 6400 cal. a BP, similar to modern conditions. Between 6000 and 3900 cal. a BP, SSSS r was consistently higher, ranging between ~9 and 13. Microfossils sensitive to salinity variations, such as Radiosperma corbiforum and Spiniferites spp., support the SSSS r estimate. In comparison with the SSSS r, the SSSpl values were consistently higher, with an average of ~14. We suggest SSSpl tend to overestimate salinity and are not as reliable as SSSSr. A multi-proxy approach, including analysis of microfossil, organic carbon content, C/N ratios and grain-size, allowed for a division of the study period into three zones (Zones I–III). Zone I (7300–6400 cal. a BP) is characterized by relatively O. centrocarpum and R. corbiforum concentrations, silt contents and C/N ratios, corresponding to the regional Littorina transgression maximum. Zone II (6400–3900 cal. a BP) is characterized by increased Spiniferites spp. and decreased R. corbiforum abundances, and by lowered C/N ratios and silt contents relative to Zone I. Zone III (3900–3500 cal. a BP) represents the start of the Post-Littorina Sea phase, indicating a shift to the modern Baltic Sea phase with decreased salinity.
(Less)
- author
- Ning, Wenxin
LU
; Andersson, Per S.
; Ghosh, Anupam
LU
; Khan, Mansoor
and Filipsson, Helena L.
LU
- organization
- publishing date
- 2017-01-01
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Boreas
- volume
- 46
- issue
- 1
- pages
- 11 pages
- publisher
- John Wiley & Sons Inc.
- external identifiers
-
- scopus:85006414922
- wos:000392869300008
- ISSN
- 0300-9483
- DOI
- 10.1111/bor.12156
- language
- English
- LU publication?
- yes
- id
- 57f9fbbb-afe8-44d8-a78c-f83d1b19c544
- date added to LUP
- 2017-03-20 13:49:35
- date last changed
- 2024-11-11 05:49:41
@article{57f9fbbb-afe8-44d8-a78c-f83d1b19c544,
abstract = {{<p>We reconstructed the past coastal environment of the Baltic Sea from c. 7300 to 3500 cal. a BP, with a focus on sea surface salinity (SSS). To quantitatively determine the SSS, two methods were employed: measurements of <sup>87</sup>Sr/<sup>86</sup>Sr ratios in mollusc shells (SSS<sub>S</sub> <sub>r</sub>) and process length variations of dinoflagellate cysts Operculodinium centrocarpum (SSS<sub>pl</sub>). The SSS<sub>S</sub> <sub>r</sub> was ~6–7 between 6800 and 6400 cal. a BP, similar to modern conditions. Between 6000 and 3900 cal. a BP, SSS<sub>S</sub> <sub>r</sub> was consistently higher, ranging between ~9 and 13. Microfossils sensitive to salinity variations, such as Radiosperma corbiforum and Spiniferites spp., support the SSS<sub>S</sub> <sub>r</sub> estimate. In comparison with the SSS<sub>S</sub> <sub>r</sub>, the SSS<sub>pl</sub> values were consistently higher, with an average of ~14. We suggest SSSpl tend to overestimate salinity and are not as reliable as SSS<sub>Sr</sub>. A multi-proxy approach, including analysis of microfossil, organic carbon content, C/N ratios and grain-size, allowed for a division of the study period into three zones (Zones I–III). Zone I (7300–6400 cal. a BP) is characterized by relatively O. centrocarpum and R. corbiforum concentrations, silt contents and C/N ratios, corresponding to the regional Littorina transgression maximum. Zone II (6400–3900 cal. a BP) is characterized by increased Spiniferites spp. and decreased R. corbiforum abundances, and by lowered C/N ratios and silt contents relative to Zone I. Zone III (3900–3500 cal. a BP) represents the start of the Post-Littorina Sea phase, indicating a shift to the modern Baltic Sea phase with decreased salinity.</p>}},
author = {{Ning, Wenxin and Andersson, Per S. and Ghosh, Anupam and Khan, Mansoor and Filipsson, Helena L.}},
issn = {{0300-9483}},
language = {{eng}},
month = {{01}},
number = {{1}},
pages = {{100--110}},
publisher = {{John Wiley & Sons Inc.}},
series = {{Boreas}},
title = {{Quantitative salinity reconstructions of the Baltic Sea during the mid-Holocene}},
url = {{http://dx.doi.org/10.1111/bor.12156}},
doi = {{10.1111/bor.12156}},
volume = {{46}},
year = {{2017}},
}